In known guide devices, each vane has one end pivotally mounted on the casing of the turbomachine about a respective axe that is radial relative to the axis of rotation of the rotor, and for this purpose the vanes have respective axial cylindrical shanks forming pivots that are pivotally guided in bearings mounted in radial cylindrical chimneys of the turbomachine casing. These bearings are generally made of bushings of material having a low coefficient of friction, such as sintered bronze, for example.
The axial chimneys of the casing are relatively short in length, such that the vanes, which are subjected to the forces exerted by the flow of gas, tend to tilt obliquely relative to their pivot axes, thereby leading to wear in the guide bushings and in the inside cylindrical surfaces of the chimneys in which the bushings are mounted. This leads to a risk of the vane pivots seizing and to an increase in the force that needs to be applied to the vanes in order to make them pivot about their pivot axes. This also leads to a risk of the radially-inner ends of the vanes coming into contact with the rotor of the turbomachine, and to corresponding risks of damage, destruction, and fire because of the intense heating that arises by the ends of the vanes rubbing against the rotor.